Fiber container and method of making the same



Feb 4, 1947- E. F. HULBERT FIBER CONTAINER AND METHOD OF MAKING THE SAME 2 Sheets-Sheet 1 Filed Nqv. 20, 1943 Feb. 4, 1947. E. F. HULBERT 1 7 FIBER CONTAINER AND METHOD OF MAKING THE SAME Filed Ndv. 20,1943 2 Sheets-Sheet 2 Patented Feb. 4, 1947 FIBER CONTAINER AND IWETHOD OF MAKING THE SAME Edwin Francis Hulbert,'Watertown, Wis, assignor to Somerville Limited, London, Ontario, Ganada, a company of Canada Application November 20, 1943, Serial No. 511,016

1 Claim. 1

This invention relates to fiber containers and method of making the same and particularly containers made of heavy paper, paper bcardand like fibrous material.

It is an object of the present invention to provide fibrous containers in which the base is firmly sealed in relation with the body.

A further object of the invention is to providea container of this character wherein the base is attached and sealed in a simple manner providing a reinforced construction, which may be waterproof if required.

A still further object of the invention is toprovide a container of the pail type having a. reinforced base, and a reinforced body extending from the base upwardly to a substantial degree.

A still further object of the invention is to provide a simple method for manufacturing fibrous container of this kind.

With these and other objects in view the invention generally comprises a container having .a firmly sealed, reinforced base to body connection which is capable of retaining liquid.

A preferred specific combination embodies a container of the tapered pail type having a reinforced body extending over a substantial area from the base upwards and including in cornbination a firmlysealed reinforced'base to body con nection.

According tothe method, a container made up of a peripherally skirted outer base piece, a tubular body and an inner base piece, is formed by positioning the skirted outer base'piece on one end of the tubular body with the skirt of'th'e said outer base piece overlapping the external surface of the body, inserting within the body the inner base piece whose peripheral edges engage the inner surface of the body, spacing the inner base piece from the outer base piece, indenting the body betweenthe outer base piece and the inner base piece to fold parts of the body and the skirt of the outer base piece inwardly, and subjecting the base pieces to pressure directed axially of the body to crease the inwardly folded parts and cause such parts to fold together while causing said base pieces to engage in firm hear-- ing engagement.

The invention will be 'clearly understood-by reference to the following detailed specification taken in conjunction with the accompanying drawings.

In the drawings: Fig. 1 is a perspective'view of the container formed according to the present invention.

i s. 2,3 and {l are schematicseotional yiews 2 illustrating succeeding steps in the method of formation of the container.

Fig. 5 is a schematic View of a step in the method showing apparatus parts for carrying out the method and illustrating the partiallyformed container in cross section.

Fig. 6 is a plan View of Fig. 5.

Fig. 7 is a perspective view of a tapered reinforced pail like container forrned'in accordance with the present invention.

Fig. 8 is a perspective view of the container shown in Fig. 7 but reversed to illustrate the base formation.

Fig. 9 is a view partly in section of apparatus for forming the tapered pail like container.

Fig. 10 is a cross section taken through the forming die.

Fig. 11 is a view similar to Fig. 5 but illustrating a succeeding step in the formation of the container.

Referring to the drawings, A indicates a container according to the present invention which vhas a cylindrical body lo, a sealed base i l and is designed to be closed by any suitable closure such as a closure member I2 that slips over the top edges of the body. The construction of the con tainer and its method of manufacture is. as follows: The cylindrical body is preferably placed on a mandrel l3 (Fig. 5) so that the lower edge of the finished container projects above the top of the mandrel. 0n the end of the mandrel an skirt ll overlaps and engages the outer surface of the body. The body is thenindented between the inner base piece it and the outer base piece to (Fig. 3) so that portion of the Wall between these two base pieces is projected inwardly in the form of a bellows-fold which also causes the skirt H of the outer base piece it to fold inwardly. Substantially simultaneously with the formation of this inward fold the outer base piece It is subjected to the pressure of a die such as I 3 (Fig. 5), so that with the indenting of the.

walls of the body and the substantially simultaneous downward pressing of the outer base piece Iii a completed base is formed such as illustrated in Fig. 1, wherein the parts are firmly interlocked- 55. such asto provide a container which willIbewaterproof if desired according to the material employed.

In this connection the inner base piece l4 and outer base piece It are caused to engage in firm bearing engagement whereas by reason of the skirt l! of the outer base piece and inwardly directed bellows fold a died, interlocked and reinforced base is provided produced under substantial pressure such as to compress the parts and set them in this relation. Preferably adhesive is employed between the skirt ii and that area of the outer surface of the body contacting the skirt ll whereas, either the inner surface of the outer base piece or inner surface of the inner base piece is coated with adhesive so that in the final pressing operation the set parts are in addition, secured together by adhesive. In this connection it should be noted that as the bellows fold is formed and pressure is applied on the outer base piece the adhesive between the skirt I1 and the area of the outer surface of the body with which it engages will be partially squeezed out to coat a portion of the bellows fold indicated by the numeral 59 (Fig. 3) so that the outer surface of the skirt ll is also adhesively united with that portion of the folded body Ill with which it engages in the final stages of pressing Thus. in the present operation the folded portion of the body and outer base piece are adhesively joined while simultaneously the inner surface of theinner base piece and the inner surface of the outer base piece are adhesively joined together. This provides an exceptionally durable and practical container of fibrous material.

The operations are preferably carried out employing the mandrel 3, a suitable pressure die H3 and a series of laterally movable die pieces 20 substantially surrounding the cylindrical body and formed with an inwardly chamfered edge 2| which, when the die pieces 28 are moved laterally towards the body Iii at the appropriate point, will have the effect of producing the bellows fold between the outer and inner base pieces and will at the same time fold in the skirt ll of the outer base piece.

The die it is moved into engagement with the base substantially simultaneously with the inward movement of the die pieces 2% whereupon the latter move outwardly as the final pressing operation is effected. Preferably a preformed base piece such as illustrated in Fig. 5'is provided wherein the base piece is pro-formed with the depression 22. Thus, in the final pressing operation when the inner and outer base pieces are united there is no tendency for the outer base piece to spring back as might occur in some instances, where the base piece is pressed inwardly by a shaped pressure die it. The resulting product illustrated in Fig. 4 may then be closed by any suitable closure such as the cover I?! illustrated in Fig. -1.

This type of construction lends itself particu larly to the formation of a container of the pail type which is of extremely durable reinforced character. This is more particularly illustrated in Figs. 7-11. The cylindrical body is first of all formed by means of a tapered mandrel 23 and a cooperating external die the latter having a plurality of radially spaced apart, axially extending grooves 25 around its inner circumference and extending from the top of the die to a point intermediate the ends of the. die where they lessenin depth and finally merge with the die wall. In this operation the cylindrical body I is placed on the mandrel 23 and the cooperating external die 24 is moved downwardly under pressure to encompass the outside of the cylindrical container, the mouth of the die being of a diameter slightly greater than the diameter of the cylindrical container. In this downward movement the tapering walls of the die 24 press the walls of the cylindrical container radially inward to impart the frusto-conical or pail-like shape and the excess material thereof is forced into the grooves 25 as shown in Fig. 10 so that the resulting product is substantially that as shown in Fig. 7 which produces a tapered pail like body 26 having a plurality of reinforcing ribs 2i which finally merge at their upper ends 28 into the body of the pail. This operation is preferably carried out with the application of heat and for this purpose the die 24 is heated and may have as illustrated a fluid chamber 29 heated by any suitable heating means 35.

The frustro-conical open ended body formed by this pressing operation is then supplied with a base. This is done preferably by placing the body on a frustro-conical mandrel of such length that it is less than the length of the fr tro-conical pail body and therefore it may have a base applied thereto in the manner described in connection with Figs. 1- 4. In this connection a suitable base is applied .to the frustro-conical ribbed body, the base having a peripheral skirt designed to overlap the outer surface of such body. An

inner base piece is placed on the top of the mandrel in the manner previously described and by indenting the body between the inner base piece and the outer base piece to form a bellows-fold such as by the movabledie pieces 20, such foldable portion of the body and the ribs carried thereby are tucked in in the bellows fold and in effect may form a series of pleats in the folding area when the base is pressed by the die l8. In this manner the ribs extend cleanlyto the base of the container as shown in Figs. 7 and 8, being in effect terminated at the base in a clean cut manner by the folding pressing operation. The effect produced is clearly illustrated in Fig. 11, the ribs protruding along the lower part of the container and terminating directly at the base though protruding beyond the periphery of the I base.

Adhesive may be employed in this type of container for causing the base parts to unite in an extremely secure manner although, as in the case of the cylindrical type of container previously described and formed under heavy pressure, the base may be connected without adhesive and the pressure employed together with the location-and form of the dies, will form a compact durable base.

The resulting product is a sturdy container having a durable base which is interlocked with the body and pressed in such a manner that having regard to the nature of the fibrous material employed the base connection is leakproof; Consequently by an extremely simple method, a practical and durable fibrous container is formed which may be used in many fields.

What I claim as my invention-is: a A fibrous container comprising a tubular end, said body being inwardly folded adjacent to the base piece to cause portions of the wall to overlap throughout its circumferenceand forming a circumferentially laterally directed inwardly projecting flange engaging and overlapping marginal portions of the inner surface of said outer base piece, a flange on said outer base piece overlying a portion of the exterior of the outer surface of the container Wall directly adjacent to the end of the body engaged by said outer base piece, a portion of said flange being inwardly directed and clamped between the inwardly folded overlapped portions of the wall, said flange of the base piece and said inwardly folded overlapped portions of the wall forming an interlocking base to body connection and an inner base piece, of a diameter substantially corresponding to the diameter of the body at said end, disposed to engage and overlie the inner surface of the outer base piece and engaging and overlying the said inwardly directed flange, said inner base piece, said inwardly folded portions of said body, said outer flange of the base piece, and said outer base piece forming afive-ply circumferential reinforcing rim at the base of the container, said outer base piece forming an external facing for said container around the circumferential edge 20 of said end of the body.

EDWIN FRANCIS HULBERT.

nErERENcns crrnn The following references are of record the file of this patent:

UNITED STATES PATENTS 

